Immersion motors built according to the NEMA standards must be capable of absorbing the axial pressure from the pump built on top of the motor, which requires that the end surface of the pivot of the motor must be of a specific predetermined height h over a contact surface on the motor housing. An adjustment of h so as to position it within the prescribed tolerance required previously that the shaft of the motor be mounted in a particular axial bearing. The bearing portion of the latter forming the sliding surface is adjustable so as to height by means of an adjustment screw centrally positioned under the axial bearing. It is also known to adjust the pivot of the motor as to height simply by inserting thin tin plates between the axial bearing and the support thereof. Such an adjustment of the height is, however, not easy to carry out during the mounting of the motor.